Stabilizing cargo during shipment and minimizing cargo changeover time between shipments are objectives of aircraft cargo transport systems. Typically, cargo shipped by air is first loaded onto specially configured pallets or into specially configured containers, commonly referred to as Unit Load Devices (“ULDs”). To facilitate movement of a ULD within an aircraft cargo compartment as the ULD is loaded, stowed, and unloaded, the deck of an aircraft cargo compartment typically includes a number of raised roller elements. These roller elements often include elongated roller trays that extend longitudinally along the length of the cargo deck, ball panel units, and the like. Once a ULD is in its final stowed position, the ULD must be restrained against both vertical and lateral movement during flight. Accordingly, the deck and sidewalls of a cargo compartment typically include a plurality of restraint devices attached at various installation points located on the deck and sidewalls that engage and secure a ULD. The installation points can be points within or along the elongated roller tray.
Two devices typically used to secure ULDs during shipment are primary and supplement restraint devices. Primary restraint devices are stationary and positioned at predetermined installation points on a cargo deck. Installation points coincide with cargo deck locations having features for receiving and retaining a restraint such as recesses, holes, slots, pins, cutouts, roller trays or the like. One example of a primary restraint is a latch that is removably fixed to an installation point and is selectively movable between a deployed (latched) position and a retracted (unlatched) position. The deployed latch receives a restraint, such as a strap. The retracted latch permits movement a ULD during loading and stowage. Primary restraints typically require tools to both engage and remove the restraint from an installation point. In addition, ancillary parts are also required.
Supplemental restraints add stability to ULDs and work cooperatively with primary restraint devices. Supplemental devices are moveable, engage a stowed ULD, and can be secured to any location capable of receiving a supplement restraint. Typically, supplemental restraints require tools for engagement and removal from an install point. In addition, ancillary parts may be required. Some have attempted to use the elongated seat track, capable of receiving a supplemental restraint, located adjacent to a roller tray on a cargo deck. Others combine a supplement and primary restraint device in one apparatus. However, ideal supplemental restraints give flexibility to a user to secure ULDs based on the circumstances of loading and stowage. Thus, the attachment of supplemental restraints may be best determined by which location best minimizes lateral or longitudinal movement of a ULD.
A need has arisen to develop supplemental restraint devices that augment primary restraints, require minimal tools, do not require ancillary parts, can be removed and secured in minimal time, and can be incorporated into an existing cargo system infrastructure.